Smith engineering students help solve run-off problem

COURTESY OF SMITH COLLEGE
Smith College seniors Catherine Betances, Monique Gagne and Rajiha Medhi, from left, helped the Northampton Department of Public Works plan for better management of stormwater run-off.
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When Smith College senior Monique Gagne can find the time to think past graduation, one image that comes to mind is a garden.

Not the vegetable kind. As an engineer, she and a team this year sprouted plans for rain gardens that will help Northampton’s Department of Public Works manage stormwater, as the city faces new rules from federal regulators.

“I’m so excited to be able to come back and look at the sites, to physically see something that I know I contributed too,” Gagne said last week.

“During our time here at Smith, we’ve grown to know and love the community, and being able to apply our engineering knowledge in a local context has been very rewarding,” she said.

Gagne is one of three Smith seniors who designed a method of identifying sustainable solutions to the problem of stormwater run-off, and the ecological hazards that entails.

The team, which also included Catherine Betances and Rajiha Medhi, showcased their work during a presentation last Friday that marked the culmination of their participation in a year-long engineering design course. Students in teams of three or four worked with external clients to apply ideas in class to real-world problems.

According to Susannah Howe, a Smith College engineering professor who has taught the class for the 10 years, it is designed to be taken by seniors as a capstone to their education and give them a taste of what it’s like to work in their field.

Over the past decade, students taking the course have completed 65 projects for 35 sponsors. According to Howe, the Northampton DPW has been involved for nine of the 10 years.

Smith project

For its project, the team worked closely with the DPW to develop environmentally sustainable stormwater strategies and help the department comply with an permit from the Environmental Protection Agency’s National Pollutant Discharge Elimination System.

According to Doug McDonald, the DPW’s stormwater coordinator, the new permit will require the department to identify city properties and consider green infrastructure options at those locations in order to continue discharging stormwater.

To meet that need, the students used geographic information software to compile an inventory of city-owned properties throughout Northampton that could be retrofitted by the DPW with “green” infrastructure solutions.

Next, they developed a spreadsheet program called the Green Infrastructure Toolbox, which allowed them to rule out green infrastructure options at each of the properties based on their characteristics. Using that information, they were able make recommendations for what could be implemented at a given site.

Finally, the students decided to take advantage of the natural process of infiltration, through which rainwater is absorbed by soil, by constructing “rain gardens” at three of the sites.

The rain gardens are shallow depressions filled with plants that allow for the capture and absorption of stormwater run-off. They will be built at the DPW’s headquarters on Locust Street, at the Smith Vocational and Agricultural High School and at the intersection of Bridge Street and Pomeroy Terrace. The gardens will help control rainwater overflow and flooding.

“One solution to the problem is upsizing the current system. This requires digging up the old pipes and replacing them with larger ones,” said Medhi. “This is expensive and destructive to the environment. So another solution is to really capitalize on this infiltration aspect, and this more green solution is often called ‘green infrastructure,’” she said.

According to Gagne, the method will also help stop pollutants from getting into local rivers.

“We designed our rain gardens to treat for the first flush. That’s what’s most important in the stormwater run-off, because the first flush, generally defined as the first half inch of rain, captures the pollutants on the ground and sends them to the local waterbodies,” said Gagne.

Those pollutants, Gagne said, will be captured by the gravel in the rain gardens, which will be periodically replaced.

“The thought is that it’s better a place for society to have it now, rather than in our rivers, where it is killing different types of species,” she said.

McDonald said that the students’ work gave the DPW a head start towards meeting the new EPA requirements. The approach outlined by the Smith engineers will continue to be used in the future.

“It’s great for us, it gives us a way to get some of the work done that we need to do, and it gives them a real-world example of learning and doing,” said McDonald.

The students were also highly receptive to the format of the course, noting that it provided them with a more holistic approach to their education.

“This class really just brought all kinds of knowledge together. Not just technical knowledge, but working with people and other things too,” said Betances. “None of the other departments on campus do similar year-long capstone projects, so it was a really great opportunity to do that.”